Advanced Classloading in J2EE

How annoying is it for many developers to have all of those damn ClassCast exceptions. Classloading isn't a simple thing when it comes to J2EE, and knowing how YOUR application server configures its classloaders for your EAR file is necessary. I hate going in to see people putting all of the jar files in the system CLASSPATH :/ This article on TheServerSide discusses a few advanced classloading schemes.